Occurrence of Organochlorine Pesticides in Human Tissues Assessed Using a Microextraction Procedure and Gas Chromatography-Mass Spectrometry.

This work focuses on the development, validation and application of an analytical method for the determination of twenty organochlorine pesticides (OCPs) in human tissues using salting out liquid-liquid extraction (SALLE) and dispersive liquid-liquid microextraction (DLLME) for sample preparation and gas chromatography-mass spectrometry (GC-MS) to analyse the obtained extracts. Measurement of the concentration levels of these toxics in tissues can be used to assess the risk of the population to exposure. The linearity of the proposed method was verified in the 10-1000 ng/g range. The sensitivity was evaluated calculating the limits of detection (LODs) for 20 OCPs (α-, β-, γ- and δ-HCH, α- and β-endosulphan, endosulphan sulphate, aldrin, dieldrin, endrin, endrin ketone, endrin aldehyde, α- and γ-chlordane, 4,4'-DDT, 4,4'-DDE, 4,4'-DDD, heptachlor, heptachlor epoxide and methoxychlor), most of them being found between 1.0 and 16 ng/g. The intra- and inter-day precision were below 12% for relative standard deviation values. The accuracy of the method was evaluated by recovery studies, which gave recovery percentages in the 85-109% range. Seven different tissues (liver, kidney, heart, spleen, lung, brain and abdominal fat) from eight autopsies were analysed and only three cases were seen to have β-HCH and 4,4'-DDE in abdominal fat, while 4,4'-DDE was also detected in the heart of one case. The rest of the samples were free of the studied OCPs at least above the corresponding LODs.